There is a device in which a door lock arranged in a door of a vehicle is locked and unlocked by an electric means when a push button located at a predetermined position of a door handle arranged outside of the door of the vehicle is operated. Specifically, the device has a switch unit including, a push button which is arranged between the door handle and a mounting bracket and penetrates a button hole formed in the door handle so that the push button is exposed to the outside of the vehicle and displaced when a physical force is inputted to the push button from the outside, and a switch main body for forming an electric signal according to a displacement of the push button.
In this case, the switch main body is fixed to the mounting bracket by fixing members such as a screw and a bolt so that the button hole, which is formed in the door handle, and an outer circumference of the push button can agree with each other (refer to Patent Document 1, for example). Due to the above structure, when the door handle is pulled forward with respect to the vehicle door, it is possible to open and close the door. When the door handle is moved backward with respect to the vehicle door, that is, when the door handle is moved to a position where the door handle is automatically returned, it becomes possible to operate the push button penetrating the button hole formed in the door handle.    Patent Document 1: JP-A-2005-090087 (Pages 4 to 7 and FIG. 1)
However, in the above structure in which the switch unit is fixed to the mounting bracket (this structure will be referred to as a fixing structure hereinafter.), the switch unit (switch main body) is fixed to the mounting bracket by the fixing member. Therefore, the fixing member must be necessarily provided in this structure. Accordingly, it is demanded to reduce the number of parts.
In the conventional switch fixing structure, the switch unit must be mounted on the mounting bracket by the fixing member while positioning is being executed so that an outer circumference of the push button can be made to agree with the button hole formed in the door handle. Therefore, the assembling work of the door handle device becomes complicated and it is difficult to reduce working time.
In the door handle device described above, an escutcheon, which holds a door handle and is fixed to the door, is formed being exposed onto a door surface so that the escutcheon can surround the door handle. The switch unit is fixed while this escutcheon is being used as a mounting base portion.
That is, in the conventional example described above, the switch unit is arranged in the door handle device on the assumption that the escutcheon, which is a mounting base body, is used in the door handle device. Therefore, in the case where only the door handle is arranged without arranging the escutcheon round the door handle for the reasons of designing, it is necessary to directly fix the switch unit to the door.
However, in order to directly fix the switch unit to the door, it is necessary to form a mounting hole on a door panel. Further, the working property is not good when the switch unit is fixed to the door.